Inorganic Chemistry Answers

From the reaction
2NaOH+CO2⟶Na2CO3+H2O,

here NaOH is the titrant and CO2 containing soln with few drops of phenolpthalein the analyte. Aim is the find out the number of moles of CO2 :

n(NaOH)=c(NaOH) × V

n(CO2)=1/2 n(NaOH)

While calculating the number of moles of NaOH required to perform the reaction, We took the conc. of NaOH (in M) and volume of the titrant (which is usually in ml). Shouldn't we convert the ml into l?

I have point group D2h ,, for 1-4 dichlorobenzene , I want to reduce the 3N representation for this

Can electrolysis be performed on aluminium oxide without the presence of carbon at its melting point?

Question 12 : Which of these elements shows polymorphism?
Pb
Sn
Si
C
Question 14 : Clays are esscentially alumina-silicates of -----
Na and K
Al or SiQuestion 18 : Which of these elements of group IV can form compounds easily in +2 oxidation state
C
Pb
Ge
Si

Question 19 : Which of these is not a component of lead-acid battery?
spongy lead
lead chloride
tetrehydrooxsulphate(VI) aci
lead oxide
Na or Ca
Ca and Si

Question 16 : Which of the following does not function as lewis acid?
Bi
N
Ar
Sb

Question 17 : Which of the following is prepared by haber process?
phosphorus
bismouthine
Ammonia
nitric acid

Question 18 : Which of the following is the most abundant uncombined element accessible to man?
N
He
O
H

Question 19 : One of these is not a raw material for the cement manufacture?
lime
alumina
silica
silicate

Question 20 : Which of the following is used as a rocket fuel?
Ammonia
,hydrazine
hydrazoic acid
phosphine

Question 11 : Which of these compounds is used in toothpastes as a source of fluoride ion to harden dental enamel
stannous fluoride
germanium fluoride
carbon tetra fluoride
Silicate fluoride

Question 12 : Silicones are a group of-------------
Organosilicon polymers
tetrachloro silicate polymer
silicon dioxide
organosilicates

Question 13 : Which form of phosphorous is most reactive?
red
white
brown
black

Question 14 : Which of these group V elements form the most stable pentahalides
B
P
As
Sb

Question 15 : Which of the group V element forms alloys with metals?
Ar
Bi
Sb
N

Question 6 : The purest form of silicon dioxide is-----
rock crystal
cristobalite
silicates
silibolite

Question 7 : Which of the following trihalides of nitrogen is stable?
chloride
bromide
floride
iodide

Question 8 : Which of the following is used in baking powder and toothpastes?
calcium phosphate
Calcium chloride
sodium tripolyphosphate
nitric acid

Question 9 : Glass is produced from mixture of silicates mainly of
K and Ca
Na and Al
K and Al
Na and Ca

Question 10 : Which of these will give a positive brown ring test?
nitric oxide
nitric dioxide
nitrogen oxide
dinitrogen tetraoxide

Question 1 : Which of the following is an oxidizing agent?
Carbon monoxide
lead dioxide
gemenium oxide
tin dioxide

Question 2 : The following are crystaline forms of silica except
quartz
cristobalite
tridymite
crystaamite

Question 3 : Which of the following is used in matches and fireworks?
nitrogen
arsenic
bismuth
red phosphorous

Question 4 : Which of the group V elements form the pp- pp multiple bonds?
Bi
N
Ar
Sb

Question 5 : Which of the following is used to decolourize bottle glasses
Sodium arsenate
arsenic acid
arsenic hydride
arsenic oxide

-5.95g of cobalt(II) carbonate were added to 40cm3 of hydrochloric acid, concentration 2.0mol/dm3
.
I] Calculate the maximum yield of cobalt(II) chloride-6-water and show that the cobalt(II) carbonate was in excess.

CoCO3 + 2HCl → CoCl2 + CO2 + H2O
CoCl2 + 6H2O → CoCl2.6H2O

} maximum yield:
} number of moles of HCl used =
} number of moles of CoCl2 formed =
} number of moles of CoCl2.6H2O formed =

} mass of one mole of CoCl2.6H2O = 238g
}maximum yield of CoCl2.6H2O = …………………………………………………..…..…g
to show that cobalt(II) carbonate is in excess:
number of moles of HCl used = ……………………….……… (use your value from above)

mass of one mole of CoCO3 = 119g

number of moles of CoCO3 in 5.95g of cobalt(II) carbonate = …………………………

(ii) Explain how these calculations show that cobalt(II) carbonate is in excess.

What if I have dissolved 10g of Hydroxyapatite in propanol and I want to adjust pH by adding nitric acid, then will the particles of Hydroxyapatite react with acid in this case? I have a doubt that it might depend on the mass of particle.